Composition and method for treatment of otitis media

ABSTRACT

A process, composition and method for increasing and enhancing mammalian eustachian tube lumen patency and pressure equalization performance is disclosed wherein an aerosolized mixture of lipid crystals comprised of a mixture of one or more lipids surfactants and one or more spreading agents selected from the group consisting of sterols, lipids, fatty acids, cholesteryl esters, phospholipids, carbohydrates, and proteins, in powder form, and one or more propellants, in which the lipid surfactants and spreading agents are not soluble, are administered through a mammalian airway orifice. Upon administration, the propellant(s) are evaporated from the mixture and the lipid crystals are deposited within a subject mammalian eustachian tube whereupon said lipid crystals come into contact with lumen surfaces of the tube forming an amorphous spread film thereupon substantially decreasing the opening pressure of the lumen. In a second preferred embodiment, a therapeutically active agent effective in the treatment of otitis media is added to the mixture of lipid crystals and upon administration of said aerosol mixture, the amorphous spread film formed thereby carries said therapeutically active agent through the eustachian tube to the tissues of the middle ear. In an alternate preferred embodiment, the afore-mentioned reduction of surface tension and delivery of therapeutically active agents is provided by a mixture of lipid crystals comprised of surfactant(s), therapeutically active agents and a propellant in which such other components are not soluble.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/639,682 filed on Aug. 16, 2000, which said application is acontinuation of U.S. patent application Ser. No. 09/450,884 filed Nov.28, 1999 and issued as U.S. Pat. No. 6,156,294 on Dec. 5, 2001.

FIELD OF INVENTION

The present invention relates to the field of pharmacologicalcompositions and methods of utilizing such compositions in order toimprove the flow of both naturally occurring fluids and pharmacologicagents through the mammalian eustachian tube.

BACKGROUND OF THE INVENTION

Otitis media is a pathological condition common to mammalian species andmost common to children. During episodes of otitis media, fluidaccumulates in the middle ear or, as it is also known, the tympaniccavity.

Acute otitis media is a condition in which fluid accumulation in themiddle ear is accompanied by signs or symptoms of ear infection(including both viral and bacterial etiologies). Such pathology mayexhibit a bulging eardrum accompanied by pain or, in some instances,perforation of the tympanic membrane. Such perforations may also beaccompanied by drainage of purulent material. In contrast, otitis mediawith effusion is typified by fluid accumulation within the tympaniccavity without signs of infection.

Both acute otitis media and otitis media with effusion may causesubstantial pain as pressure increases, positively or negatively, withinthe confines of the tympanic chamber. Antibiotics, steroids, andantibiotics in combination with steroids have been utilized to treatotitis media. Antihistamine/decongestants have also been utilized in thetreatment of otitis media with effusion.

The anatomical features of the middle ear define what can be describedas a sealed chamber. On its lateral border, the middle ear iseffectively isolated from the external auditory meatus (in the absenceof a punctured ear drum), by the tympanic membrane. Medially, the middleear is effectively sealed from the inner ear by a bony wall. Theposterior wall of the tympanic cavity communicates with a large, buteffectively sealed mastoid antrum. Only the anterior wall of the middleear contains a passageway for effective communication outside of thetympanic cavity. There, a natural pathway provided by the auditory or,as it is also known, the eustachian tube, provides communication withthe nasopharynx.

As stated above, during episodes of acute otitis media, the painfulincreased middle ear pressure may naturally resolve through a resultantperforation of, and drainage through, the tympanic membrane. However,the increased fluid pressure associated with otitis media with effusiondoes not resolve via this mechanism. In fact, for those patientssuffering otitis media for prolonged periods of time, and especially forthose evidencing significant associated hearing loss, myringotomy withthe placement of a tympanostomy tube may be indicated as a means ofequalizing middle ear pressure and in order to restore normal hearing.Recently, laser surgery has also been utilized to provide an aperturethrough the tympanic membrane through which the fluid trapped within themiddle ear may drain. Besides the perforations of the eardrum providedby infection (acute otitis media), myringotomy and laser surgery, theeustachian tube, a natural middle ear drainage path described above, isprovided by mammalian anatomy. Unfortunately, during episodes of otitismedia with effusion (OME), a time when the natural pathway and pressurerelief functions of the eustachian tube would be most useful, theincrease pressure required to open the lumen (as described in moredetail above and below), effectively eliminates this means of relievingmiddle ear pressurization. Reduced patency of the eustachian tube isbelieved to be one of the primary causes of OME in pediatric patients.In fact, it is known that OME elevates eustachian tube opening pressureindependent of other pathological conditions effecting this conduit. Theterm “opening pressure” as it is utilized throughout this disclosure andwithin the claims, refers to the pressure, typically measured inmillimeters of mercury, necessary to cause the lumen of the auditorytube to open and provide a patent pathway between the nasopharynx andtympanic cavity.

Treatment of otitis media by means of administration ofanti-inflammatory agents, antibiotics, decongestants and/oranti-histamines, or combinations thereof, is limited in effectivenessas, in the absence of perforation, there is presently no method fordirect application of such drugs directly to target tissues of theeustachian tube and/or middle ear. Systemic applications of drugs viaparenteral or oral routes, while eventually reaching the eustachian tubeand middle ear, may have adverse systemic effects and, more importantly,are not especially effective at delivering a concentrated dose of theapplicable drugs where they are truly needed, directly to the targettissues. Simply put, the sealed chamber anatomy of the middle ear has,up until the present time, constituted a barrier to direct drugapplication.

Although the central lumen of the eustachian tube does provide a pathwayto the tympanic cavity, it is, as described below, ordinarily closed andresistant to fluid passage due to its inherent anatomical configuration.During episodes of otitis media, the relatively high surface tensionspresent at the air/liquid interface located upon the epithelial liningof the tube lumen further increase the opening pressure required to openthis channel. Although direct application of therapeutically activeagents, effective in the treatment of otitis media, to the lumen of theeustachian tube, and via the lumen to the middle ear, would be highlyadvantageous in treating otitis media, no method or composition has yetbeen disclosed capable of overcoming the surface tension within the tubelumen so as to facilitate opening of the tube and transport of suchdrugs throughout the lumen and on to the tissues of the middle ear. Whatis needed is a composition and method of applying same, especiallyformulated and adapted to decrease the surface tension of the auditorytube so as to decrease the opening pressure thereof, thereby providing apatent conduit for therapeutic agents, effective in the treatment ofotitis media, to travel through said tube to effectively treat saidcondition.

Pathological conditions can arise from, and can cause changes in surfacetension values of air/liquid interfaces in other organs of mammaliananatomy. The naturally occurring “surfactant system” secreted upon theepithelial lining of the lung which is deficient in cases of R.D.S. isknown to be comprised of a complex mixture of lipids, proteins andcarbohydrates (as described in a recent review: Surfactants and theLining of the Lung, The John Hopkinds University Press, Baltimore,1988). The prime function of the surfactant system is to stabilize thealveoli and associated small airways against collapse by decreasing thesurface tension at the air/liquid interface. It is now believed that theaction of the phospholipid component of the surfactant system is theprincipal source of the powerful surface tension reduction effect of thenaturally occurring surfactant system of the lung. More specifically, itis known that the fully saturated diacylphospholipids, principally,dipalmitoyl phosphatidylcholine (DPPC) provide liquid balance andanti-collapse properties to the lung's epithelial lining. In addition toDPPC, spreading agents, also found within the naturally occurringsurfactant system, assist DPPC in rapidly forming a uniform spread filmon the air/liquid surfaces of the lung. Such spreading agents includecholesteryl esters such as, for example, cholesteryl palmitate (CP);phospholipids such as, for example, diacylophosphatidylglycerols (PG),diacylphosphatidylethanolamines (PE), diacylphosphatidylserines (PS),diacylphosphatidylinositols (PI), sphingomelin (Sph) and Cardiolipin(Card); and virtually and other phospholipid, and of thelysophospholipids; or any of the plasmalogens, dialklylphospholipids,phosphonolipids, carbohydrates and proteins, such as, for example,albumin, pulmonary surfactant proteins A, B, C and D. The naturallyoccurring surfactant system is further described in U.S. Pat. No.5,306,483.

DPPC has been administered to infants with respiratory distress syndromeas a therapeutic measure. For this purpose, DPPC has been administeredby means of an aqueous aerosol generator (utilized with an incubator inwhich the infant resided during treatment). Endotracheal administrationhas also been utilized. DPPC therapy has been typified as utilizingnatural surfactants (harvested from porcine or bovine lungs), orartificial, commercially synthesized compounds.

It has also heretofore been disclosed to utilize therapeutic agents, incombination with surfactant/spreading agents to effectively administerdrug therapy uniformly throughout the epithelial lining of the lung.U.S. Pat. No. 5,306,483 (the “'483 patent”) discloses a process toprepare lipid crystalline figures in fluorocarbon propellants for thedelivery of therapeutically active substances which form amorphousfluids on delivery at the air/liquid interface of the lung and which canbe utilized as an effective drug delivery system. More specifically,said patent discloses a process comprising (a) preparing a mixture ofone or more lipids of the group of phospholipids known asphosphatidylcholines and one or more spreading agents, in powder formand a therapeutically active substance and one or more fluorocarbonpropellants, said lipids, spreading agents and therapeutically activesubstances being insoluble in the propellants; and (b) evaporating thepropellants from the mixture. The '483 patent teaches the combination ofdipalmitoyl phosphatidylcholine (DPPC) or any of the other fullysaturated Acyl chain phospholipids, 80.0 to 99.5% by weight, and otherspreading agents, for example, phospholipids such as, but not limited toPG, PE, PS, PI, lysophospholipids, plasmalogens, dialkylphospholipids,diether phosphonolipids, Cardiolipin, sphingomyelin, 0.5 to 20.0%weight, neutral lipids like cholesteryl esters such as, but no limitedto, cholesteryl palmitate, cholesteryl oleate, cholesteryl stearate ormixtures thereof, 0.5 to 10% by weight, carbohydrates, such as, but notlimited to, glucose, fructose, galactose, pneumogalactan, dextrose (ormixtures thereof), 0.5 to 10% by weight, and proteins such as, but notlimited to albumin, pulmonary surfactant specific proteins A, B, C, andD 0.5 to 10% by weight, compounds in lipid-crystalline structures influorocarbon (both chloro- and hydrofluorocarbon) propellants in whichtherapeutically active agents, drugs and other materials can be carriedinto the lungs after release from and through metered dose nebulizer.The spreading agents referred to in the '483 patent are compounds suchas the above-described phospholipids, lysophospholipids, plasmalogens,dialklyphospholipids, phosphonolipids, carbohydrates and proteins. Thefunction of the spreading agent is to assist DPPC, or otherphospholipids such as, for example, DPPG, in rapidly adsorbing andforming a spread film upon the air/liquid surfaces of the lungs. Inaddition, the '483 patent also discloses a process for preparing suchlipid crystalline figures in fluorocarbon propellants without atherapeutically active substance for use as a tear (as for the eye).

Although the '483 patent does disclose a process for preparing a drugdelivery system especially adapted for uniformly applying a therapeuticagent to the epithelial lining of the lung, heretofore, no method orcomposition has been disclosed in the past that is particularly adapted,configured and formulated for the delivery of therapeutic agents totarget tissues of the eustachian tube, or, via the eustachian tube, themiddle ear.

Otitis media can, due to fluid accumulation, cause significant pressure,both positive and negative, in the afore-mentioned confines of themiddle ear. Pressure differentials between the middle ear and thesurrounding atmosphere, whether due to the addition of such fluids, ordue to the relative decrease or increases of ambient atmosphericpressure, can cause great pain and discomfort. Such pressure conditionssubject the tympanic membrane, and the associated pain receptors, tobulging and stretching. In addition, the accumulation of fluids, and theresulting static tension applied to the tympanic membrane, can greatlyreduce hearing.

As mentioned above, the eustachian tube is specifically adapted toprovide communication between the middle ear (a sealed chamber), andambient atmospheric pressure, by providing a pathway between thetympanic cavity and the nasopharynx. Thus the auditory tube serves as apressure equalization means for the middle ear. However, in order toprovide this equalization function, and, at the same time, allow propermiddle ear sound conduction, the eustachian tube, and the pathway itprovides between the middle ear and the nasopharynx, are ordinarilyclosed. The lumen of the tube, as discussed below, is ordinarily openonly during the act of swallowing and other movements that causecontraction of the attached musculature.

In humans, the eustachian tube is, on the average, 3.5 cm in length. Theposterior one third of the tube is comprised of a bony wall with theanterior two thirds of the tubular structure being cartilaginous incomposition. The auditory tube provides, by means of a central lumen, afluid passage way between the nasopharynx and middle ear. However, thesomewhat flattened medial and lateral walls of the tube are ordinarilyin direct contact occluding and effectively limiting passage of liquidsand gasses therethrough and allowing optimal sound conduction functionof the middle ear which requires a sealed chamber. During swallowing,the tensor veli palatini muscle, which inserts into the lateral surfaceof the cartilaginous portion of the tube, contracts and pulls the wallof the tube laterally opening the central lumen thereby providing thecommunicating pathway needed for fluid flow between the middle ear andthe nasopharynx. The action of the muscle upon the tube is needed toovercome the surface tension attracting the flattened medial and lateralwalls of the central lumen together as well as the elastic recoil of thetube cartilage which also tends to close the lumen. The surface tensionis due to the sero-mucous secretions found on the epithelial lining ofthe lumen.

In normal physiologic function, the sero-mucous secretions of theauditory tube, and the relatively low surface tensions they produce atthe lateral and medial walls of the lumen, do not interfere with thenormal opening and related pressure equalization functions of theauditory tube. However, middle ear, tube and upper respiratoryinfections and/or inflammatory conditions, such as allergies, cangreatly effect the nature and increase the amount of the secretionsfound upon the lumen surface. Generally, such pathologic conditionsgreatly increase the surface tension of the lumen walls by increasingthe relative amount of mucoid secretions, effectively interfering with,or completely preventing the opening of the tube. In addition, thetissues of the eustachian tube may become inflamed and engorged withfluids and cause further increases in opening pressures.

The above-described alterations in the nature and amount of secretionsas well as inflammation of tube tissues are common during episodes ofotitis media. Therefore, at a time when eustachian tube drainage of themiddle ear would be highly desirable, this normally effectivephysiologic means of eliminating painful pressure often associated withsuch pathology is either hindered or completely eliminated. The commoncold, flu, hay fever and other allergies can also result in eustachiantube failure for the same reason. However, inflammatory changes in tubetissues and lumen secretions are not the exclusive cause of suchauditory tube failures.

Rapid changes in ambient pressure may also inhibit or completely preventnormal equalization functions of the auditory tube. If ambient pressurechanges too quickly, the pressure gradient between the atmosphere andtympanic cavity may be too great to allow lumen opening. For example,the pressure within the tympanic cavity of a diver who, for example,ascends from a relatively deep dive without effectively and continuouslyequilibrating his or her middle ear through action of the eustachiantube (by swallowing, wiggling the jaw or utilizing other means tocontract the attached musculature) can experience terrific pain know asa “squeeze” which may be very difficult to overcome. Such situations aremore likely in such instances when, for example, a diver engages in suchactivity, wisely or unwisely, while he is or she is suffering from anallergy or cold (for the above-described reasons). By rising in depthwithout frequent and effective eustachian tube function, the relativelylow ambient pressure surrounding the diver effectively seals off theeustachian tubes communication with the relatively highly pressurizedmiddle ear. A diver, under such circumstances, may simply descend back afew feet to a depth where the pressure gradient is non-existent orminimal, and thereby lower the opening pressure of the auditory tubeallowing it to open and equalize the tympanic cavity. However, apassenger on a plane is in no position to change altitudes to obtain a“second chance” to equilibrate. If such a passenger is unable tofrequently and effectively equilibrate the middle ear during altitudechanges due to, for example, increased secretions within the tuberesulting from a cold, he or she is forced to bear significant pain.

Although, as described below, surfactant compositions, both natural andartificial, have been heretofore known, formulated and utilized todecrease surface tension within the lung, no such compositions,processes or methods for administering said compositions, have beenheretofore suggested, taught or disclosed in regards to decreasing thesurface tension within the lumen of the eustachian tube. Likewise, nomethod has heretofore been known which provides an effective decrease inopening resistance of the eustachian tube while simultaneously providingthe delivery of therapeutically active agents, effective in thetreatment of otitis media directly to the epithelial lining of theeustachian tube and middle ear.

SUMMARY OF THE INVENTION

Now, in accordance with the present invention, a method of increasingand enhancing mammalian eustachian tube lumen patency and pressureequalization performance is disclosed.

In a first preferred embodiment of the present invention, a mixture ofone or more lipids and one or more spreading agents selected from thegroup consisting of sterols, lipids, fatty acids, cholesteryl esters,phospholipids, carbohydrates, and proteins, all in powder form, and oneor more propellants is prepared. The propellant is selected to be one inwhich the one or more lipids and one or more spreading agents are notsoluble so as to enable, in part, the formation of the below-describedlipid crystals. Propellants such as, for example, fluorocarbonpropellants may be advantageously selected. The lipids and the spreadingagents are likewise advantageously selected to be insoluble in thepropellants.

The lipid surfactants utilized in practicing the method of the presentinvention are selected to be present in an amount sufficient toeffectively reduce the surface tension of the liquid/air interface ofthe epithelial surface to which they are applied, while the spreadingagents are present in an amount sufficient to effectively distribute thelipids upon said surface. The term, “effectively reduce surface tension”as utilized throughout this application and in the claims, refers tothat weight percentage range of lipid which, when present in saidmixture of lipid crystals, provides a clinically significant decrease ineustachian tube opening pressure so as to allow increased pressureequalization function. The term, “effectively distribute the lipids uponsaid surface” refers to that weight percentage range of spreading agentthat is required in order to provide adequate spreading and distributionof the lipids so as to form an amorphous spread film upon the epitheliallined surfaces of the lumen so that the lipid surfactant effectssufficient lumenal surface area enabling the afore-mentioned reductionin opening pressure.

It has been found that the above-described clinically significantdecrease in eustachian tube opening pressure and effective distributionof lipids can be effected by a mixture comprised of from about 99.99 toabout 30 weight percent lipid surfactant and from about 70 to about 0.01spreading agent. Increased effectiveness is provided by a preferredmixture comprised of from about 99.99 to about 50 weight percent lipidsurfactant and from about 50 to about 0.01 weight percent spreadingagent, both based on total weight of the mixture. However, it is stillfurther preferred that the lipid surfactants utilized in practicing themethod of the present invention are present in an amount of about 80 to99.5 percent by weight and the spreading agents are present in an amountof about 0.5 to about 20 percent by weight, both based upon the totalweight of the mixture. Combination of the one or more lipids, one ormore spreading agents and one or more propellants results in theformation of lipid crystals described in more detail, below. A metereddose of the mixture of lipid crystals is then administered, viainhalation through an external airway, into a mammal upon which thepresent method is practiced. It is preferred that the mixture beadministered via a nasal orifice. However, it is also contemplated thatthe mixture of lipid crystals may also be administered via oralinhalation.

Upon administration, the propellant(s) are evaporated from the mixtureand the lipid crystals are deposited at a nasopharyngeal, or as it mayalso be described, an anterior terminus, of a subject mammalianeustachian tube whereupon said lipid crystals come into contact withlumen surfaces of the tube. Upon contact with the air/liquid interfacesof the eustachian tube lumen, the mixture of lipid crystals forms anamorphous spread film upon said air/liquid interface effectivelydecreasing the opening pressure thereof.

The lipid crystals deposited upon the lumen surfaces and air/liquidinterface thereupon is comprised of one or more lipids which areadvantageously selected to demonstrate powerful surfactant activity. Inaddition, the spreading agent combined therewith provides substantiallycomplete distribution of the surfactant over and upon the air/liquidinterface resident upon the epithelial lining thereby resulting in asubstantial decrease in lumen opening pressure. In turn, the decrease inlumen opening pressure results in greater patency of the eustachian tubeand provides a resultant increase in fluid conduction/equalizingfunction of this anatomical structure.

In a second preferred embodiment of the present invention, a method ofadministering therapeutically active agents, effective in the treatmentof otitis media, directly to mammalian eustachian tube and middle eartarget tissues as well as a process for preparing a medicament forproviding such treatment is disclosed. In the second embodiment of thepresent invention, a mixture of one or more lipids, one or morespreading agents, one or more therapeutically active agent(s), effectivein the treatment of otitis media, and one or more propellants isprepared. The one or more lipids and spreading agents are advantageouslyselected from the group consisting of lipids, fatty acids, cholesterylesters, phospholipids, carbohydrates, and proteins, all being in powderform. The one or more lipid surfactant, spreading agents andtherapeutically active agent(s), effective in the treatment of otitismedia, and the propellants are selected so that the lipid surfactantsand spreading agents are insoluble in the propellants. The lipidsutilized in practicing the method of the second preferred embodiment ofthe present invention are selected to be present in an amount sufficientto effectively reduce the surface tension of the liquid/air interface ofthe epithelial lining to which they are applied, while the spreadingagents are present in an amount sufficient to effectively distribute thelipids to form an amorphous spread film upon said surface, while notadversely increasing surface tension. Effective reduction of surfacetension is evidenced, as discussed below, in increased eustachian tubepatency.

It has been found that the above-described clinically significantdecrease in eustachian tube opening pressure and effective distributionof lipids can be effected by a mixture comprised of from about 99.99 toabout 30 weight percent lipid surfactant and from about 70 to about 0.01spreading agent. However, it is preferred, and increased effectivenessis provided by a mixture comprised of from about 99.99 to about 50weight percent lipid surfactant and from about 50 to about 0.01 weightpercent spreading agent, both based on total weight of the mixture.However, it is still further preferred that in practicing the method ofthe second embodiment of the present invention, the lipid surfactantsare present in an amount of about 80 to 99.5 percent by weight and thespreading agents are present in an amount of about 0.5 to about 20percent by weight, both based upon the total weight of said mixture. Themixture resulting from the combination of lipid surfactant(s), spreadingagent(s) and therapeutically active agent and propellant forms lipidcrystals which act as carriers for said therapeutically active agent. Ametered dose of the mixture of lipid crystals is then administered,preferably via an external nasal airway, into a mammal upon which themethod is practiced. A suitable bottle equipped with a metered dosevalve and nasal administration adaptor is advantageously utilized forthis purpose. However, all embodiments of the present invention alsocontemplate administration via oral inhalation of said mixture.

Upon administration of the lipid crystal mixture, the propellants, carrythe lipid crystals in combination with therapeutically active agent(s)effective in the treatment of otitis media to the nasopharyngealterminus of the eustachian tube whereupon the propellant(s) evaporate.The lipid crystals and therapeutically active agent is then depositedupon the tissues of the eustachian tube, including the epithelial linedlumen, whereupon the mixture forms an amorphous spread film effectivelycarrying said therapeutically active agent effective in the treatment ofotitis media to the epithelial lining of the eustachian tube lumen andtarget tissues of the eustachian tube and middle ear. As stated infurther detail below, the therapeutically active agent is advantageouslyselected to be effective in the treatment of otitis media. Therefore,the second preferred method of the present invention provides a methodof administering therapeutically active agents directly to lumensurfaces of mammalian eustachian tubes, and also, by means of saideustachian tube lumen, to middle ear target tissues wherein saidtherapeutically active agents provide effective treatment for otitismedia while, in addition, providing the same increased eustachian tubepatency and performance as the first embodiment.

The lipid crystals deposited upon the lumen surfaces and air/liquidinterface thereof are comprised of one or more lipids which areadvantageously selected to demonstrate powerful surfactant activity andto serve as a carrier for selected therapeutic agent(s). In addition,the spreading agent deposited therewith provides effective distributionof the surfactant and therapeutic agent(s) throughout the lumenair/liquid surface to form an amorphous spread film thereupon resultingin substantial decreases in lumen opening pressure. In turn, thedecrease in lumen opening pressure provides greater patency of theeustachian tube. Thus a resultant increase in fluidconduction/equalizing function of this anatomical structure is providedwhile simultaneously providing direct application of therapeuticallyactive agent to target tissues of the auditory tube and middle ear.

The lipids utilized in practicing the method and process of the presentinvention may be advantageously selected to be phospholipids, neutrallipids or mixtures thereof. The phospholipids utilized may be furtheradvantageously selected to be any phospholipid of the class known asphosphatidlycholine including any fully saturated diacylphosphatidlycholine including 1,2 dipalmitoyl phosphatidylcholine(DPPC); a diacylphosphatidylglycerol; a diacylphosphatidylethanolamine;a diacylphosphatidylserine; a diacylphosphatidylinositol; sphingomyelin,Cardiolipin, lysophospholipid; a plasmalogen; a diether phosphonolipid;or a dialklyphospholipid.

The lipids utilized in practicing the method and process of the presentinvention may also be advantageously selected to be either plant oranimal sterols. For example, cholesterol, cholecalciferol and ergosterolmay be selected. In addition fatty acids, such as, for example, palmiticacid and oleic acid may also be selected.

The cholesteryl esters utilized in practicing the method of the presentinvention may be advantageously selected to be, for example, cholesterylpalmitate, cholesteryl oleate, cholesteryl stearate or mixtures thereof.Carbohydrates utilized in the present invention may be advantageouslyselected to be, for example, glucose, fructose, galactose,pneumogalactan, dextrose or mixtures thereof. Proteins especially suitedand advantageously selected for use in the present invention includealbumin, pulmonary surfactant specific proteins A or B or C or D, theirsynthetic analogs, and mixtures thereof.

As stated in further detail below, the therapeutically active agent isadvantageously selected to be effective in the treatment of otitis mediaas well as agents effective in the treatment of the underlying causesthereof provoking said immune responses leading to the above-describedinflammatory responses. For example, such agents may be selected to beeffective in the treatment of mycotic, viral or bacterial infections,(as well as combinations thereof) underlying and causative of saidinflammatory reactions. Therefore, the second preferred method of thepresent invention provides a method of administering therapeuticallyactive agents directly to the epithelial lining of the eustachian tubewherein said therapeutically active agents provide effective treatmentfor the subject inflammatory condition such as, for example edema—aswell as the underlying causes thereof—while, simultaneously, the mixtureof lipid crystals act to directly and effectively decrease the surfacetension of the lumen.

In a first alternate embodiment of the present invention, a compound,process and method is disclosed providing administration oftherapeutically active agents, effective in the treatment of otitismedia, directly to mammalian eustachian tube and middle ear targettissues as well as a process for preparing a medicament for providingsuch treatment. In practicing the method and process of the firstalternate embodiment of the present invention, a mixture of one or morelipid surfactants, one or more therapeutically active agent(s),effective in the treatment of otitis media, and/or the underlying causethereof, and one or more propellants—in which said lipid surfactant andtherapeutically active agents are not soluble—is prepared. The lipidsurfactant is selected from the group consisting of sterols, lipids,fatty acids, cholesteryl esters, phospholipids, carbohydrates andproteins. The therapeutic agent may be selected from any of the afore orbelow-mentioned therapeutically active agents so as to provide desiredtherapeutic effects (regarding treatment of inflammatory conditions andthe causative agents thereof). In such embodiments the mixture of lipidsis comprised of a lipid surfactant and a therapeutic agent and the lipidsurfactant and therapeutic agent are advantageously selected to bepresent in the same weight ratios as those described above and below inregards to those embodiments incorporating surfactant/spreading agentcomponents—the therapeutic agent being present in the same respectiveweight percentage range as the spreading agent in such embodiments. Forexample, an effective result may be provided by a mixture comprised offrom about 99.99 to about 30 weight percent lipid surfactant and fromabout 70 to about 0.01 therapeutic agent. Increased effectiveness isprovided by a preferred mixture comprised of from about 99.99 to about50 weight percent lipid surfactant and from about 50 to about 0.01weight percent therapeutically active, both based on total weight of themixture. However, it is still further preferred said mixture may becomprised of from about 80 to about 99.5 weight percent lipid surfactantand from about 20 to about 0.5 weight percent therapeutically activeagent, based upon total weight of said mixture.

In practicing the first alternative embodiment, the therapeuticallyactive agent may be selected as a pharmacologic agent which, inaddition, is also selected from the group consisting of sterols, lipids,fatty acids, cholesteryl esters, phospholipids, carbohydrates andproteins. In such embodiments, the therapeutically active agent acts inaccordance with its own pharmacologic function, as well as providingspreading agent function.

As described above, the therapeutic agent is selected to be presentwithin the above-described weight ranges and in an amount sufficient totreat the afore-mentioned otitis media inflammatory condition and/orcausative agents. The remainder of the mixture is comprised of one ormore of the above-described lipid surfactants which act to reduce thesurface tension of the liquid/air interface of the epithelial lining ofthe eustachian tube, while the therapeutically active agent providestreatment of the inflammatory condition effecting the eustachian tube,and/or the causative agents thereof. Upon evaporation of the propellant,an aerosolized mixture of lipid crystals is formed.

Upon administration of the mixture of lipid crystals and therapeuticagent to the eustachian tube via, for example, a metered dose bottle,the lipid crystal come into contact, and form an amorphous spread filmupon the air/liquid interface resident upon the epithelial liningthereof. The surfactant spread film reduces the surface tension of thelumen while simultaneously delivering the therapeutic active agents tothe afore-mentioned target tissues. The propellants may beadvantageously selected to be fluorocarbon propellants such as, forexample, chlorofluorocarbon propellants, hydrofluorocarbons or mixturesthereof. The present invention contemplates the use of carbon dioxide asa propellant as a suitable propellant. It is also contemplated that thepresent invention may incorporate and select any pharmaceutical grade,hypo-allergenic propellant in which the other components of the mixtureare not soluble—the propellant, lipids, spreading agents andtherapeutically active agents must be selected so none of theafore-mentioned surfactants, spreading agents or therapeutically activeagents are soluble, and thus dissolved, within the propellant. Thepropellant is thus selected in order to enable the formation of theaerosolized mixture of lipid crystals, discussed below.

DETAILED DESCRIPTION OF THE INVENTION

Throughout this specification and claims, the phrase “therapeuticallyactive agent” includes any substance which is capable of altering abiologic, physiologic and/or immunologic function, in nature or degreeand includes those substances generally referred to pharmacologicagents, drugs and gene therapy agents; the term “fluorocarbons” includesthe class of both chlorofluorocarbons and hydrofluorocarbons; the termlipids includes the class of phospholipids including, but not limited toPC, PG, PE, PI and Cardiolipin; and the phrase “spreading agent(s)”refer to and includes PG, PE, PS, PI, Sph., Card., lysophospholipids,plasmalogens, dialkylphospholipids, and all others in the classphospholipid as well as cholesteryl esters (like CP), proteins andcarbohydrates.

Throughout this specification and claims, the phrase “spreadingagent(s)” refers to compounds, as listed above, which assist the one ormore lipid surfactants such as, for example, DPPC, in rapidly adsorbingand forming an amorphous spread film on air/liquid interfaces such asthat found upon the epithelial lined lumen of the auditory tube. Inaddition, the compounds referred to as “spreading agent(s)”, togetherwith the one or more lipids, are responsible for achieving andmaintaining biophysical properties including, but not limited to,reduction of intermolecular attractive forces, surface tension, and theresultant attractive forces generated thereby, that tend to causeopposed surfaces, such as the lateral and medial epithelial lined lumenwalls of the auditory tube, to adhere to each other. As discussed below,in certain preferred embodiments of the present invention, thetherapeutically active agent(s) is advantageously selected from thegroup consisting of sterols, lipids, fatty acids, cholesteryl esters,phospholipids, carbohydrates, and proteins, all in powder form. In suchembodiments, the therapeutic agent(s) provides, in addition to theabove-described pharmacologic effects, the functions of the spreadingagent (without need for a separate spreading agent.)

The major lipid component utilized in practicing a preferred embodimentof the present invention is advantageously selected to be phospholipid1,2 dipalmitoyl, phosphatidlycholine (DPPC). DPPC is the most surfaceactive of the phospholipids or any of the subclass of fully saturatedacyl chain phospholipids. That is to say that DPPC, in combination withany spreading agent(s) disclosed herein, has a maximum effect inreducing surface tension at an air/liquid interface.

Another, minor lipid component that also acts as a spreading agent forthe major component is advantageously selected to bediacylphosphatidylglycerol (PG). The number of carbon atoms in the acylchains R and R′, (see PG formula below) can vary between 8 and 22 andmay or may not be fully saturated. DPPC and PG can be synthesized.However, since DPPC and PG are the main phospholipid constituents ofcells, they are also readily extractable from such cells by non-polarsolvents, i.e., chloroform, ether, acetone. DPPC's structural formulais:

and PG's structural formula is:

Phospholipids such as DPPC and CP may be obtained commercially, in ahighly purified form from Fluka Chemical Co. of Ronkonkoma, N.Y.; SigmaChemical CO. of St. Louis Mo.; and Avanti Polar Lipids of Birmingham,Ala. and Primedica of Cambridge, Mass.

DPPC and PG are preferred component(s) advantageously utilized in thepresent inventions methods for administering therapeutically activeagents to the middle ear and auditory tube. In addition, these lipidsincrease the pressure equalizing performance of the auditory tube bydirect result of their surfactant qualities. DPPC may be selected to bepresent in the composition over a fairly wide range. It is preferredthat weight percentages of from about 80% to about 99.5% DPPC by isselected. However, the DPPC component may be selected to be present inan amount of from about 99.99% to about 50% by weight without undueinterference in desired properties needed for drug delivery andsurfactant activity.

Throughout this specification and in the claims, the phrase “increasingpressure equalization performance of the auditory tube” and “increasingthe pressure equalization performance of the eustachian tube” both referto the increased ease and ability of a mammal upon which the presentmethod is practiced, to utilize the pathway provided by the lumen of theeustachian tube to equalize the pressure of the middle ear with ambientpressure surrounding the mammal. The increased ease and ability is theresult of the decrease in opening pressure of the lumen of the mammalianeustachian tube provided by the present invention.

Another lipid that can be utilized in practicing the methods of thepresent invention is cholesteryl palmitate (CP), which also serves as aspreading agent. This cholesteryl ester is a neutral lipid which belongsto a class of organic compounds that are also cell constituents and areextractable by non-polar solvents such as chloroform, methanol, ether,etc. The structural formula of CP is:

CP may be obtained commercially in a highly purified form from FlukaChemical Co. and Sigma Chemical Co. The CP component constitutes a minorportion of the composition. It is selected to be present in a weightpercentage sufficient so as to enable effective spread and distributionof the lipid upon the mucosal surfaces. It is preferred that the CPcomponent be selected to be present in an amount ranging from about 0.5%to 20% by weight. Also, the preferred ratio of DPPC to CP is from about99.5 DPPC to 0.5 CP by weight. However, the CP component may be selectedto be present in an amount of from about 50 to about 0.01% by weight andthe DPPC component may be selected to be percent in an amount of fromabout 99.99% to about 0.50 weight % without undue interference indesired properties needed for drug delivery and surfactant activity.

The term “therapeutically active agent” and “therapeutically activeagent effective in the treatment of otitis media,” as utilized in andthroughout this specification and claims, refers to those drugseffective in treatment of otitis media including, but not limited toanti-inflammatory agents including, for example, betamethasone,including, for example, betamethasone dipropionate and betamethasonevalerate as well as all other effective formulations; de-congestiveagents such as phenylephrine, including, for example, phenylephrine HCLand phenylephrine bitartrate and all other effective formulationsthereof; antibiotics including, for example erythromycin, amoxicillin,zythromax, and augmentin (amoxicillin and clavuliic acid) in all oftheir effective formulations and gene therapy agents. Such gene therapyagents, as the term is used herein, refers to a biochemical substance—aswell as vectors thereof—selected from the group including, but notlimited to, proteins, peptides or amino acids; nucleic acids such asDNA, including full length genes or fragments thereof derived fromgenomic, cDNA, or artificial coding sequences, gene regulatory elements,RNA including mRNA, tRNA, ribosomal RNA, ribozymes and anitsense RNA,oligonucleotides, oligoribonucleotides, deoxyribonucleotides andribonucleotides as such agents may exist as isolated and purifiedcompounds or in unpurified mixtures, such as tissue, cell or celllysate. In addition, such agents may be naturally occurring, synthetic,or a mixture thereof. The term “all of their effective formulations” asused throughout this specification and in the claims refers to thosespecific species of a particular therapeutic agent effective in thetreatment of otitis media.

The combination of lipid component(s) and spreading agent component(s)disclosed herein, may be referred to, collectively, as the “carrier”when said combination is mixed with a therapeutically active agent so asto act as a carrier therefore. When practicing the method of the presentinvention wherein therapeutically active agents are administereddirectly to mammalian eustachian tube and middle ear tissues, it ispreferred that carrier, the mixture of one or more lipids and one ormore spreading agents, be comprised of a mixture of DPPC and CP in a200:1 ratio (by weight). However, it has been found that a ratio rangeof from 5:1 to 300:1 (DPPC/CP) will also produce an effective carrierfor this embodiment. If, for example, the therapeutic agent is selectedto be betamethasone, the weight ratio of betamethasone to carrier(DPPC/CP) is advantageously selected to be 1 microgram betamethasone to5 milligrams carrier. However, it has been found that a weight ratiorange of 0.5 to 1000 micrograms betamethasone/5 milligrams carrieryields an effective and functional mixture.

In certain embodiments of the present invention, the therapeuticallyactive agent is advantageously selected from the group consisting ofsterols, lipids, fatty acids, cholesteryl esters, phospholipids,carbohydrates, and proteins, all in powder form. In such embodiments, inaddition to acting as pharmacologic agents, drugs or a gene therapymodality, the therapeutically active agent also serves as a spreadingagent. In such instances, any of the afore-mentioned surfactants of thepresent invention may be combined with a therapeutic agents selectedfrom the above-identified group at the same weight ratio ranges selectedfor spreading agent/surfactant mixtures. Upon administration (andevaporation of propellant) a mixture of lipid crystals is formed thatacts to decrease opening pressure of the eustachian tube whilesimultaneously carrying the therapeutically active agent to targettissues of the eustachian tube and middle ear.

When practicing the method of the present invention wherein thetherapeutically active agent is selected to be phenylephrine it ispreferred to select the weight ratio of phenylephrine to carrier to be160 micrograms/995 milligrams. However, it has also been found that aweight ratio range of from 50 to 5000 micrograms (phenylephrine): 995 to900 milligrams carrier, respectively, forms an effective mixture andfunctional mixture. The term “effective and functional mixture” asutilized throughout this application and in the claims refers to theeffectiveness of the mixture of lipid crystals in combination with saidtherapeutically active agent resulting from the combinations disclosedherein in: (a) reaching the target tissue of the eustachian tube andmiddle ear; (b) reducing the surface tension thereupon; and (c)delivering a uniform dose of therapeutic agent directly to andeffectively spreading upon said tissues so as to effectively bringsymptomatic relief and/or resolution of the afore-mentioned pathologicalconditions including otitis media.

When practicing the method of the present invention wherein thetherapeutically active agent is selected to be the antibioticerythromycin, the ratio of erythromycin to carrier is advantageouslyselected to be 200 mg antibiotic to 800 mg carrier (DPPC/CP) by weight.However, a weight range of from 50 to 200 mg erythromycin: from 950 to800 mg carrier, respectively, has been found to be fully effective inpracticing the present method.

The fluorocarbon propellants utilized in practicing certain preferredembodiments of the method of the present invention, namely:trichlorodifluoromethane, dichlorodifluoromethane, andtetrafluoromethane or mixtures thereof, which are commercially availablefrom Union Carbide Corp., Danbury, Conn. and Armstrong Laboratories,West Roxbury Mass. are advantageously selected for formation of thelipid crystalline figures of the present invention. The fluorocarbonpropellants are present over a range of 2 to 30 times the amount, byweight, of lipid, but components of lipid and fluorocarbon propellantsboth are needed in order to obtain the required lipid crystallinefigures.

In practicing the methods of the present invention whereintherapeutically effective agents are administered directly to the middleear for the treatment of otitis media, DPPC is advantageously selectedas the major lipid component since the amphoteric nature of thisphospholipid allows the molecule to act as a carrier for any drug ortherapeutic agent. However, the presence of a charge on other lipidcomponents (a negative charge on PG, for example) would alter andfurther improve the carrying capacity of the lipid crystals for aparticular therapeutic agent.

In addition to erythromycin and amoxicillin, the method of the presentinvention also contemplates selecting zythromax and Augmentin(amoxicillin+clavulinic acid) as antibiotic therapeutic agents. However,because of the highly amphoteric nature of the carrier utilized herein,the use of any presently known and available, as well as antibioticdeveloped in the future capable of providing effective treatment ofinfections of the middle ear and eustachian tube are contemplated andfully functional with the methods and compositions herein.

EXAMPLE 1

The aerosolized drug delivery system of the present invention wasprepared from chromatographically pure (greater than 99%) DPPC and CP.Both materials were purchased from suppliers on the commercial marketwhere they are available from several chemical supply houses.Specifically, the DPPC and CP were purchased from Sigma Chem., St Louis,Mo. All purchased materials were checked for purity by standardchromatographic analysis. The betamethasone utilized in this example wasalso purchased from Sigma Chemical. The DPPC and CP were then mixed inthe dry powder form in a weight ratio of 200:1 (DPPC:CP). To 5milligrams of the resultant carrier, 1 microgram of betamethasone wasadded in order to yield a weight ratio of 5000:1 (carrier:betamethasone). Then 5 grams of this mixture was suspended in 55 gramsof the first propellant, trichloromonofluoromethane (P11) and subdividedinto 30 ml. Wheaton plastic-coated glass bottles with a 20 mm neckfinish. Valois metered dose valves were then crimped onto each bottlethrough which 40 gms of the second propellant, dichlorodifluoromethane(P12), was passed. The filled bottles were then gently shaken todisperse the solids that are insoluble in the propellants. The bottleswere thereafter immersed in a water bath to test for leaks and thenfitted with a nasal administration adapter. The suspension washomogenous. After standing at room temperature for about three days, apellicle forms on top of the propellants but is easily re-suspended bygentle shaking. The size of the metering valve can be varied to deliverfrom 1 mg up to 5.4 mg of the DPPC:CP:Betamethasone aerosolized mixture.However, metered dose valves having a greater dosing range are alsocontemplated and can be utilized in other embodiments of the presentinvention.

EXAMPLE II

The aerosolized drug delivery system of the present invention wasprepared from chromatographically pure (greater than 99%) DPPC and CP.Both materials were purchased from suppliers on the commercial marketwhere they are available from several chemical supply houses.Specifically, the DPPC and CP were purchased from Sigma Chem., St Louis,Mo. The phenylephrine utilized in this example can also be purchasedfrom Sigma Chem., St Louis, Mo. All purchased materials were checked forpurity by standard chromatographic analysis. The DPPC and CP were thenmixed in the dry powder form in a weight ratio of 200:1 (DPPC:CP).Thereafter, to 995 milligrams of the resultant carrier, 160 microgramsof phenylephrine was added so as to yield an approximate 6200:1 weightratio of carrier to phenylephrine. Then 5 grams of the resultant mixture(DPPC/CP/phenylephrine) was suspended in 55 grams of the firstpropellant, trichloromonofluoromethane (P11) and subdivided into 30 ml.Wheaton plastic-coated glass bottles with a 20 mm neck finish. Valoismetered dose valves were then crimped onto each bottle through which 40gms of the second propellant, dichlorodifluoromethane (P12), was passed.The filled bottles were then gently shaken to disperse the solids thatare insoluble in the propellants and nasal administration adaptors. Thebottles were immersed in a water bath to test for leaks and then fittedwith a nasal administration adapter. The suspension was homogenous.After standing at room temperature for about three days, a pellicleforms on top of the propellants but is easily re-suspended by gentleshaking. The size of the metering valve can be varied to deliver from 1mg up to 5.4 mg of the DPPC:CP: phenylephrine aerosolized mixture.However, metered dose valves having a greater dosing range are alsocontemplated and can be advantageously utilized in practicing themethods of the present invention.

EXAMPLE III

The aerosolized drug delivery system of the present invention wasprepared from chromatographically pure (greater than 99%) DPPC and CP.Both materials were purchased from suppliers on the commercial marketwhere they are available from several chemical supply houses.Specifically, the DPPC and CP were purchased from Sigma Chem., St Louis,Mo. The erythromycin utilized in this example can also be purchased fromSigma Chem., St Louis, Mo. All purchased materials were checked forpurity by standard chromatographic analysis. The DPPC and CP were thenmixed in the dry powder form in a weight ratio of 200:1 (DPPC:CP).Thereafter, to 800 milligrams of the resultant carrier, 200 milligramsof erythromycin was added so as to yield an approximate 4:1 weight ratioof carrier to erythromycin. Then 5 grams of the resultant mixture(DPPC/CP/erythromycin) was suspended in 55 grams of the firstpropellant, trichloromonofluoromethane (P11) and subdivided into 30 ml.Wheaton plastic-coated glass bottles with a 20 mm neck finish. Valoismetered dose valves were then crimped onto each bottle through which 40gms of the second propellant, dichlorodifluoromethane (P12), was passed.The filled bottles were then gently shaken to disperse the solids thatare insoluble in the propellants. The bottles were immersed in a waterbath to test for leaks and then fitted with a nasal administrationadapter. The suspension was homogenous. After standing at roomtemperature for about three days, a pellicle forms on top of thepropellants but is easily re-suspended by gentle shaking. The size ofthe metering valve can be varied to deliver from 1 mg up to 5.4 mg ofthe DPPC:CP: erythromycin aerosolized mixture. However, metered dosevalves having a greater dosing range are are also contemplated and canbe advantageously utilized in practicing the methods of the presentinvention.

EXAMPLE IV

The aerosolized drug delivery system of the present invention wasprepared from chromatographically pure (greater than 99%) DPPC, PG andCP. All of these materials were purchased from suppliers on thecommercial market where they are available from several chemical supplyhouses. Specifically, the DPPC, CP and PG were purchased from SigmaChem., St Louis, Mo. The erythromycin utilized in this example can alsobe purchased from Sigma Chem. All purchased materials were checked forpurity by standard chromatographic analysis. The DPPC, PG and CP werethen mixed in the dry powder form in a weight ratio of 7:1:0.35(DPPC:PG:CP). Thereafter, to 800 milligrams of the resultant carrier,200 milligrams of erythromycin was added so as to yield an approximate4:1 weight ratio of carrier to erythromycin. Then 5 grams of thismixture was suspended in 55 grams of the first propellant,trichloromonofluoromethane (P11) and subdivided into 30 ml. Wheatonplastic-coated glass bottles with a 20 mm neck finish. Valois meteringvalves were crimped onto each bottle through which 40 gms of the secondpropellant, dichlorodifluoromethane (P12), was passed. The filledbottles were then gently shaken to disperse the solids that areinsoluble in the propellants. The bottles were thereafter immersed in awater bath to test for leaks and then fitted with a nasal administrationadapter. The suspension was homogenous. After standing at roomtemperature for about three days, a pellicle forms on top of thepropellants but was easily resuspended by gentle shaking. The size ofthe metering valve can be varied to deliver from 1 mg up to 5.4 mg ofthe DPPC:PG:CP: erythromycin aerosolized mixture.

EXAMPLE V

Chromatographically pure DPPC and CP (99% pure) were obtained fromAvanti Polar Lipids Co. of Birmingham, Ala. and Sigma Chemical Co. ofSt. Louis, Mo.

DPPC and CP were mixed in a weight ratio of 200:1 (DPPC:CP). Then 5grams of this mixture was suspended in 55 grams of the first propellant,trichloromonofluoromethane (P11) and subdivided into 30 ml. Wheatonplastic-coated glass bottles with a 20 mm neck finish. Valois meteringvalves were crimped onto each bottle through which 40 gms of the secondpropellant, dichlorodifluoromethane (P12), was passed. The filledbottles were then gently shaken to disperse the solids that areinsoluble in the propellants. The bottles were thereafter immersed in awater bath to test for leaks and then fitted with a nasal inhalationadapter. The suspension was homogenous. After standing at roomtemperature for about three days, a pellicle forms on top of thepropellants but was easily re-suspended by gentle shaking. The size ofthe metering valve can be varied to deliver from 5.4 mg up to 1.0 mg ofthe DPPC:CP aerosolized mixture.

The afore-described Examples “I” through “IV” are specific embodimentsof the aerosolized drug delivery system utilized in practicing themethod of the present invention. Each of the afore-mentioned Examples“I” through “IV” are administered by releasing a metered dose of themixtures, by means of a nasal administration adaptor, through the nose.The aerosolized mixture, propelled by the above-described propellants,is then deposited about the anterior terminus of the eustachian tube atits communication with the nasopharynx. Thereafter, the crystallinelipid figures come in contact with mammalian auditory tube tissue and,forms an amorphous spread film layer upon the air/liquid interfaceresident upon the epithelial lined lumen. The spread film, in turn,spreads both the surfactant and the therapeutic agent carried therebythroughout the lumen of the tube and upon the air/liquid interfaceresident upon the epithelial lining of the tissues of both the auditorytube and middle ear.

In the above-described Example “I”, wherein the therapeutically activeagent is the anti-inflammatory betamethasone, the agent acts directlyupon the auditory tube itself, reducing the excess mucoid secretions andswelling of the auditory tube characteristic of OME. Both excess mucoidsecretions and inflammatory swelling of the tube substantially increaseauditory tube opening pressure, or, in other words, both mucoidsecretions and tissue swelling tend to increase the force required toopen the lumen and form a patent duct between the middle ear andnasopharynx. However, DPPC and/or DPPC/PG lipids act independently ofselected therapeutic agent(s) to reduce the surface tension of the lumenby reducing the intermolecular and surface charges found at theair/interface of the secretion covered lumen.

The present invention also contemplates the use of antibiotics such as,for example, erythromycin (Example “III” and “IV”), amoxicillin,zythromax and augmentin (amoxicillin+clavulinic acid). In suchembodiments, the DPPC and/or DPPC/PG act to introduce such drugs to theauditory tube and middle ear in the same manner as described immediatelyabove in regards to anti-inflammatory agents. However, while DPPC andDPPC/PG aerosolized mixtures act as carriers for such drugs, they alsocontinue to provide the decrease in surface tension and opening pressureof the eustachian tube. Therefore, in instances in which the method ofthe present invention is utilized to treat a bacterial infection of themiddle ear, direct application of antibiotic therapy to the tympaniccavity/eustachian tube bacterial source, and increased patency of theauditory tube is provided.

In Example “V”, above, preparation of an aerosolized mixture of lipidcrystals for use in practicing the method of the present invention isdisclosed that is advantageously formulated for enhancing pressureequalization performance of mammalian eustachian tubes without the useof a therapeutically active agent. In practicing the second preferredembodiment of the present invention, the aerosolized mixture, propelledby the above-described propellants, is deposited about the anteriorterminus of the eustachian tube at its communication with thenasopharynx. Thereafter, the crystalline lipid figures come in contactwith auditory tube and form an amorphous spread film layer upon theair/liquid interface of the epithelial lined lumen which, in turn,spreads the lipid mixture throughout the lumen of the tube and into themiddle ear. At the same time, surface tension of an air/liquid interfacelocated upon the eustachian tube's epithelial lined lumen is reduced toprovide said increased performance. In this example, a process,composition and method of enhancing pressure equalization performance ofmammalian eustachian tubes is disclosed wherein surface tension of anair/liquid interface located upon the eustachian tube's epithelial linedlumen is reduced to provide said increased performance. However notherapeutically active agent is included in the aerosolized mixture orcontemplated in this embodiment. Increased auditory tube patency isprovided by means of interaction of the surfactant/spreading agentcombination alone. However, in many instances, especially in the absenceof infection and/or inflammatory disease, use of anti-inflammatory andantibiotics may not be necessary. As stated above, a principal cause ofOME is thought to be reduced eustachian tube patency. Since OME, asopposed to acute otitis media, occurs in the absence of infection, useof antibiotics would be of little to no value in the treatment of suchpathology. In addition, for those embodiments and applications of thepresent invention specifically directed at enhancing performance of theauditory tube for individuals who experience equilibration difficulties(solely in connection with flying or diving), elimination of unnecessarydrugs would be highly desirable.

Effect of Aerosolized Lipid Crystals on Passive Opening Pressure of theEustachian Tube in an Animal Model

The aerosolized lipid crystal mixture described in “Example V”, above,was administered, through the nose, to Mongolian Gerbils and WistarMice. Administration of the mixture resulted in a reduction, from aninitial opening pressure of 36.82+/−2.03 mmHG to 29.16+/−2.67—anapproximately 18% reduction in the Mongolian Gerbils—and from an initialopening pressure of 43.1+/−1.43 mmHG to 32.1+/−2.21—a reduction inopening pressure of approximately 23% in Wister Mice—. Therefore, thecomposition and method of the present invention effectively increasedeustachian tube patency by means of an exogenous nasally administeredsurfactant.

Effect of Aeoosolized Lipid Crystals With and Without TherapeuticallyActive Agent Upon OME

Otitis media with effusion (OME) was developed in 75 gerbils by intratympanic injection of 100-ug/mL solution of lipopolysaccharide derivedfrom Klebsiella pneumoniae. The animals were grouped and the followingdrugs were sprayed intra nasally, prepared in an aerosolized metereddose inhaler (MDI) viz 1) Placebo (normal saline); 2) Surfactant alone(DPPC:CP (200:1); 3) Surfactant with betamethasone (5 mg carrier to 10micrograms betamethasone diproprionate); 4) Surfactant withphenylephrine (995 mg carrier to 160 micrograms phenylephrine HCl).In-vivo Typanometry and Micro-otoscopy was done on the 3^(rd), 5^(th),7^(th), 9^(th), 10^(th), 12^(th), 15^(th), 16^(th), 22^(nd) and 30^(th)days after the development of OME. Resolution of OME was observed bymicro-otoscopy on the 6^(th), day in the surfactant with betamethasonegroup, on the 10^(th) day with the surfactant alone group, and on the16^(th) day for all other groups. The experimental results demonstratethe effectiveness of those methods of the present infection utilizinganti-inflammatory agents, as well as those utilizing the disclosedaerosolized lipid crystals alone, in providing effective treatment ofotitis media.

Structural Characteristics

Particle Size and Gross Configuration

Particle size of the nebulized crystals produced and utilized inpracticing the present invention is, as discussed below, is importantfor effective administration. The size (diameter) of the lipid crystalswere therefore determined utilizing a cascade impactor. Flow through theimpactor was adjusted to be substantially identical to the flow from anebulizer utilized in practicing the disclosed method. All of the lipidcrystals were found to have a diameter equal to or less than 16 microns.The diameter of about 95 percent of the particles were found to be equalto or less than 4 microns in diameter. Of the particles found to be 4microns or less, half were, in fact, 1 micron in diameter. The meandiameter demonstrated by the lipid crystals utilized in the method ofthe present invention was 1.75+/−0.25 microns.

Micronization may be advantageously utilized in order to insure reducedparticle size. Therefore, the methods of the present invention alsocontemplate the use of a micronization mill such as, for example, the“DYNO” mill, type KDL, manufactured by Glen Mills Inc., of New Jersey inthe preparation of the aerosolized mixture. For example, approximately13.33 grams of CP and 83 g of DPPC powder were weighed and transferredto a bead mill within the milling chamber of a DYNO mill (having about480 cc of glass beads). The chamber was then sealed. Thereafter, 1 literof HFC-134a was added and the system chilled to about −10° C. at apressure of approximately 65 psi. Milling was achieved in about 1 hour.Thereafter, the resultant slurry was utilized to fill 15 mil epoxyphenolic lined aluminum cans (Safet Embamet, St. Florantine, France),fitted with Valois metering valves (DFI/ACT/kematal, Valois, Le Neuborg,France with Micron-4 acuators (also Valois). A laser particle sizer,model 2600c, Malvern Instruments, Inc., was thereafter utilized to sizethe resultant particles as shown in Table “1”, below. This dataindicates that approximately 90% of the particles emitted fro the valveand actuator system are under 7 μm or less in diameter. The meandiameter (arithmetic mean) is approximately 5 μm and the mass medianaerodynamic diameter (MMAD) is about 3.4 μm with a geometric standarddeviation (GSD) of about 0.5. Particle size results in physicallyunstable dispersions should change dramatically over a few days ofundisturbed storage.

TABLE 1 Particle Size Summary Day 90 50 Number Percentile Percentile % ≦10 μm MMAD GSD 1 6.9 μm 5.1 μm 100 3.4 0.5 2 6.8 μm 4.8 μm 99.9 3.5 0.53 7.3 μm 5.4 μm 100.0 3.5 0.5 4 6.5 μm 4.6 μm 99.9 3.2 0.5 5 6.8 μm 4.7μm 100.0 3.4 0.5 Mean 6.9 ± 0.3 μm 4.9 ± 0.3 μm 100.0 3.4 ± 0.1 0.5

Structural characteristics of the mixture of lipid crystals utilized inpracticing the present invention were further assessed by capturing theaerosolized particles on standard scanning electron microscopic gridsfixed to glass slides at 22° C., (dry). The lipids deposited on glassboth as dry particles and as coalesced droplets. The latter evaporatedimmediately leaving dry lipid. The dry lipids, were fixed in osmiumvapor (O_(s)O₄), coated and viewed with a scanning electron microscope.Crystalline figures about 100 angstroms thick, were grouped in clumps onthe dry surface. This is a unique configuration.

Crystalline Structure

The mixture of one or more lipids, one or more spreading and one or morepropellants disclosed in the present invention is especially formulatedand combined to form a unique crystalline structure with physicaldimensions highly advantageous to all embodiments. For example, thecrystalline structure results in, as discussed above, a mean particlesize of 1.75 microns. The minute physical dimensions of the individualnebulized particles enables the propellant utilized in practicing thepresent invention to easily and effectively transfer the disclosedmixture to and throughout the desired target tissue. A larger physicalconfigurations such as, for example, a liposome, would not enable suchdiminutive particle size within and such effective physical transport bythe propellant.

Functional Properties

The aerosolized mixture of the present invention is crystalline. Thecrystalline nature of the mixture imparts increased efficiency ofparticle dispersion within the aerosol mist applied by means of ametered-dose nebulizer. Upon application, the propellant, such as, forexample a fluorocarbon medium, (either chlorofluorocarbon orhydrofluorocarbon), vaporizes rapidly and the DPPC/CP, DPPC/CP drug,DPPC/PG drug or DPPC/PG/CP drug dispersion deposits on an aqueoussurface at 37° C., initially in the crystalline form, and then,instantaneously, spreads over the surface as an amorphous surface film.In embodiments wherein a therapeutic is combined with the carrier, thedrug likewise is spread, throughout the aqueous surface.

The surfactant/spreading agent functions and characteristics of themethod, process and composition of the present invention were tested asfollows. Aerosolized crystalline figures of the present invention wereimpacted upon a liquid surface (normal saline solution, NSS) at 37° C.,100% humidity in a surface balance resulted in a rapid spreading of aprincipally amorphous film that covered the entire surface (18.1 cm²).Surface tension of the film was measured during expansion andcompression at 37° C., 100% humidity. Film expansion to 110.4 cm²produced a surface tension of 72 dynes/cm and compression to 18.1 cm²lowered surface tension to less than 1 dyne/cm.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and notlimitation, and there is no intention, in the use of such terms andexpressions, of excluding equivalents of the features shown anddescribed or portions thereof, it being recognized that the scope of theinvention is defined and limited only by the following claims.

I claim:
 1. A method of increasing and enhancing mammalian eustachiantube lumen patency and pressure equalization performance comprisingadministering a dose of a mixture of lipid crystals, as an aerosol,through an external airway of a mammal, said mixture being comprised ofat least one lipid surfactant in an amount effective in lowering surfacetension of an air/liquid interface resident upon epithelial tissuelining said lumen, at least one spreading agent in an amount effectivein distributing said surfactant within said lumen and at least onepropellant in which said surfactants and spreading agents are notsoluble, said surfactants and said spreading agents being selected fromthe group consisting of sterols, lipids, fatty acids, cholesterylesters, phospholipids, carbohydrates, and proteins, all in powder form;whereupon, when said mixture is so administered, said propellants areevaporated from said mixture as said lipid crystals come into contactwith, and deposit upon the epithelial lining of the eustachian tube andform an amorphous spread film thereupon so as to reduce the openingpressure of said tube.
 2. The method of claim 1 wherein said amount oflipid surfactant is selected to be present in an amount of from about 50to about 99.99 weight percent and wherein said spreading agent isselected to be present in an amount of from about 0.01 to about 50weight percent.
 3. The method of claim 1 wherein said lipid surfactantis selected to be present in an amount of from about 80 to about 99.5weight percent and wherein said spreading agent is selected to bepresent in an amount of from about 0.5 to about 20 weight percent. 4.The method of claim 1 wherein a metered dose inhalation device is filledwith said mixture of lipid crystals and thereafter said device isutilized to administer a metered dose of said mixture through anexternal nasal orifice of said mammal.
 5. The method of claim 1 whereina metered dose inhalation device is filled with said mixture of lipidcrystals and thereafter said device is utilized to administer a metereddose of said mixture via oral inhalation.
 6. The method of claim 1wherein the sterols are cholesterol, ergosterol, cholecalciferol andmixtures thereof.
 7. The method of claim 1 wherein the fatty acids arepalmitic acid, oleic acid and mixtures thereof.
 8. The method of claim 1wherein the lipids are phospholipids, neutral lipids and mixturesthereof.
 9. The method of claim 8 wherein the phospholipids are any of aclass known as phosphatidylcholines.
 10. The method of claim 9 whereinthe phosphatidylcholine is any fully saturated diacylphosphatidylcholine.
 11. The method of claim 10 wherein the fullysaturated diacyl phosphatidylcholine is 1,2 dipalmitoylphosphatidylcholine.
 12. The method of claim 8 wherein the phospholipidis a diacylphosphatidylglycerol, diacylphosphatidylethanolamime,diacylphosphatidylserine, diacylphosphatidylinositol, sphingomelin,Cardiolipin, lysophospholipid, plasmalogen, diether phosphonolipid,dialkylphospholipid, and a mixture thereof.
 13. The method of claim 1wherein the carbohydrates are glucose, fructose, galactose,pneumogalactan, dextrose and mixtures thereof.
 14. The method of claim 1wherein the protein is selected from albumin and pulmonary surfactantspecific proteins A or B or C or D and mixtures thereof.
 15. The methodof claim 1 wherein the cholesteryl ester is cholesteryl palmitate,cholesteryl oleate, cholesteryl stearate and mixtures thereof.
 16. Themethod of claim 1 wherein the propellants are fluorocarbons.
 17. Themethod of claim 16 wherein the fluorocarbon is a chlorofluorocarbon,hydrofluorocarbon and mixtures thereof.
 18. The method of claim 1wherein the propellant is carbon dioxide.
 19. The method of claim 1wherein the propellant is any pharmaceutical grade hypo-allergenicpropellant in which neither the surfactant or spreading agent aresoluble.
 20. The method of claim 1 wherein 95 percent of said crystalsare a particle size no greater than 4 microns in diameter.
 21. A methodof administering therapeutic agents, effective in the treatment ofotitis media, directly to mammalian eustachian tube and middle eartissues while simultaneously increasing and enhancing eustachian tubelumen patency and pressure equalization performance comprisingadministering a dose of a mixture of lipid crystals in combination withsaid therapeutic agents, as an aerosol, through an external airway of amammal, said mixture being comprised of at least one lipid surfactant inan amount effective in lowering surface tension of an air/liquidinterface resident upon epithelial tissue lining said lumen, at leastone spreading agent in an amount effective in distributing saidsurfactants upon said interface within said lumen, at least onetherapeutically active agent effective in the treatment of otitis mediaand at least one propellants, said surfactants and said spreading agentsbeing selected from the group consisting of sterols, lipids, fattyacids, cholesteryl esters, phospholipids, carbohydrates, and proteins,said surfactants, spreading agents and therapeutically active agents allbeing in powder form and insoluble in the propellants, whereupon, whensaid mixture is so administered, said propellants evaporate from saidmixture as said lipid crystals come into contact with, and deposit uponthe epithelial lining of the eustachian tube and form an amorphousspread film thereupon so as to reduce the opening pressure of said tubewhile distributing said therapeutically active agent within said lumenand to said middle ear tissues.
 22. The method of claim 21 wherein saidlipid surfactant is selected to be present in an amount of from about 50to about 99.99 weight percent and wherein said spreading agent isselected to be present in an amount of from about 0.01 to about 50weight percent.
 23. The method of claim 21 wherein said lipid surfactantis selected to be present in an amount of from about 80 to about 99.5weight percent and wherein said spreading agent is selected to bepresent in an amount of from about 0.5 to about 20 weight percent. 24.The method of claim 21 wherein a metered dose inhalation device isfilled with said mixture of lipid crystals in combination with saidtherapeutically active agent and thereafter said device is utilized toadminister a metered dose of said mixture through an external nasalorifice of said mammal.
 25. The method of claim 21 wherein a metereddose inhalation device is filled with said mixture of lipid crystals incombination with said therapeutically active agent and thereafter saiddevice is utilized to administer a metered dose of said mixture by meansof oral inhalation.
 26. The method of claim 21 wherein the sterols arecholesterol, ergosterol, cholecalciferol and mixtures thereof.
 27. Themethod of claim 21 wherein the fatty acids are palmitic acid, oleic acidand mixtures thereof.
 28. The method of claim 21 wherein the lipids arephospholipids, neutral lipids and mixtures thereof.
 29. The method ofclaim 28 wherein the phospholipids are any of a class known asphosphatidylcholines.
 30. The method of claim 29 wherein thephosphatidylcholine is any fully saturated diacyl phosphatidylcholine.31. The method of claim 30 wherein the fully saturated diacylphosphatidylcholine is 1,2 dipalmitoyl phosphatidylcholine.
 32. Themethod of claim 28 wherein the phospholipid is adiacylphosphatidylglycerol, diacylphosphatidylethanolamime,diacylphosphatidylserine, diacylphosphatidylinositol, sphingomelin,Cardiolipin, lysophospholipid, plasmalogen, diether phosphonolipid,dialkylphospholipid, and a mixture thereof.
 33. The method of claim 21wherein the carbohydrates are glucose, fructose, galactose,pneumogalactan, dextrose and mixtures thereof.
 34. The method of claim21 wherein the protein is selected from albumin and pulmonary surfactantspecific proteins A or B or C or D and mixtures thereof.
 35. The methodof claim 21 wherein the cholesteryl ester is cholesteryl palmitate,cholesteryl oleate, cholesteryl stearate and mixture thereof.
 36. Themethod of claim 21 wherein said therapeutically active agent is ananti-inflammatory, antibiotic, decongestant and gene therapy agent. 37.The method of claim 36 wherein said anti-inflammatory agent isbetamethasone.
 38. The method of claim 36 wherein said antibioitic iserythromycin, amoxicillin, zythromax and amoxicillia/elavalanstepotassium.
 39. The method of claim 36 wherein said decongestant isphenylephrine.
 40. The method of claim 21 wherein the propellants arefluorocarbons.
 41. The method of claim 40 wherein the fluorocarbon is achlorofluorocarbon, hydrofluorocarbon and mixtures thereof.
 42. Themethod of claim 21 wherein the propellant is carbon dioxide.
 43. Themethod of claim 21 wherein the propellant is any pharmaceutical grade,hypo-allergenic propellant in which neither the surfactant, spreadingagent or therapeutically active agent are soluble.
 44. The method ofclaim 21 wherein 95 percent of said crystals and a particle size nogreater than 4 microns in diameter.
 45. A method of administeringtherapeutic agents, effective in the treatment of otitis media, directlyto mammalian eustachian tube and middle ear tissues while simultaneouslyincreasing and enhancing eustachian tube lumen patency and pressureequalization performance comprising administering a dose of a mixture oflipid crystals in combination with said therapeutic agents, as anaerosolized mixture of lipid crystals, through an external airway of amammal, said mixture being comprised of at least one lipid surfactant inan amount effective in lowering surface tension of an air/liquidinterface resident upon epithelial tissue lining said lumen, at leastone therapeutically active agent effective in the treatment of otitismedia and at least one propellant, said lipid surfactants being selectedfrom the group consisting of sterols, lipids, fatty acids, cholesterylesters, phospholipids, carbohydrates, and proteins, said surfactants andtherapeutically active agents all being in powder form and insoluble inthe propellants, whereupon, when said mixture of lipid crystals is soadministered, said propellants evaporate from said mixture as said lipidcrystals come into contact with, and deposit upon the epithelial liningof the eustachian tube so as to reduce the opening pressure of said tubewhile distributing said therapeutically active agent within said lumenand to said middle ear tissues.
 46. The method of claim 45 wherein saidlipid surfactant is selected to be present in an amount of from about 50to about 99.99 weight percent and wherein said therapeutically activeagent is selected to be present in an amount of from about 0.01 to about50 weight percent.
 47. The method of claim 45 wherein said lipidsurfactant is selected to be present in an amount of from about 80 toabout 99.5 weight percent and wherein said therapeutically active agentis selected to be present in an amount of from about 0.5 to about 20weight percent.
 48. The method of claim 45 wherein a metered doseinhalation device is filled with said mixture of lipid crystals incombination with said therapeutically active agent and thereafter saiddevice is utilized to administer a metered dose of said mixture throughan external nasal orifice of said mammal.
 49. The method of claim 45wherein a metered dose inhalation device is filled with said mixture oflipid crystals in combination with said therapeutically active agent andthereafter said device is utilized to administer a metered dose of saidmixture by means of oral inhalation.
 50. The method of claim 45 whereinthe sterols are cholesterol, ergosterol, cholecalciferol and mixturesthereof.
 51. The method of claim 45 wherein the fatty acids are palmiticacid, oleic acid and mixtures thereof.
 52. The method of claim 45wherein the lipids are phospholipids, neutral lipids and mixturesthereof.
 53. The method of claim 52 wherein the phospholipids are any ofa class known as phosphatidylcholines.
 54. The method of claim 53wherein the phosphatidylcholine is any fully saturated diacylphosphatidylcholine.
 55. The method of claim 54 wherein the fullysaturated diacyl phosphatidylcholine is 1,2 dipalmitoylphosphatidylcholine.
 56. The method of claim 52 wherein the phospholipidis a diacylphosphatidylglycerol, diacylphosphatidylethanolamime,diacylphosphatidylserine, diacylphosphatidylinositol, sphingomelin,Cardiolipin, lysophospholipid, plasmalogen, diether phosphonolipid,dialkylphospholipid, and a mixture thereof.
 57. The method of claim 45wherein the carbohydrates are glucose, fructose, galactose,pneumogalactan, dextrose and mixtures thereof.
 58. The method of claim45 wherein the protein is selected from albumin and pulmonary surfactantspecific proteins A or B or C or D and mixtures thereof.
 59. The methodof claim 45 wherein the cholesteryl ester is cholesteryl palmitate,cholesteryl oleate, cholesteryl stearate and mixture thereof.
 60. Themethod of claim 45 wherein said therapeutically active agent is ananti-inflammatory, antibiotic, decongestant or gene therapy agent. 61.The method of claim 60 wherein said anti-inflammatory agent isbetamethasone.
 62. The method of claim 60 wherein said antibiotic iserythromycin, amoxicillin, zythromax and amoxicillia/elavalanstepotassium.
 63. The method of claim 60 wherein said decongestant isphenylephrine.
 64. The method of claim 45 wherein the propellants arefluorocarbons.
 65. The method of claim 64 wherein the fluorocarbon is achlorofluorocarbon, hydrofluorocarbon and mixtures thereof.
 66. Themethod of claim 45 wherein the propellant is carbon dioxide.
 67. Themethod of claim 45 wherein the propellant is selected to be anypharmaceutical grade, hypo-allergenic propellant in which neither the atleast one surfactant or therapeutically active agent are soluble. 68.The method of claim 45 wherein the therapeutic agent is selected fromthe group consisting of sterols, lipids, fatty acids, cholesterylesters, phospholipids, carbohydrates, and proteins.